2. Academic Validation
  3. Target identification for small-molecule discovery in the FOXO3a tumor-suppressor pathway using a biodiverse peptide library

Target identification for small-molecule discovery in the FOXO3a tumor-suppressor pathway using a biodiverse peptide library

  • Cell Chem Biol. 2021 Nov 18;28(11):1602-1615.e9. doi: 10.1016/j.chembiol.2021.05.009.
Amy Emery 1,  Bryn S Hardwick 1,  Alex T Crooks 1,  Nadia Milech 2,  Paul M Watt 2,  Chandan Mithra 3,  Vikrant Kumar 3,  Saranya Giridharan 3,  Gayathri Sadasivam 3,  Subashini Mathivanan 3,  Sneha Sudhakar 3,  Sneha Bairy 3,  Kavitha Bharatham 3,  Manjunath A Hurakadli 3,  Thazhe K Prasad 3,  Neelagandan Kamariah 3,  Markus Muellner 4,  Miguel Coelho 4,  Christopher J Torrance 4,  Grahame J McKenzie 5,  Ashok R Venkitaraman 6
Affiliations

Affiliations

  • 1 Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK.
  • 2 Telethon Kids Institute, Centre for Child Health Research, University of Western Australia & PYC Therapeutics Limited, Nedlands, WA 6009, Australia.
  • 3 Center for Chemical Biology & Therapeutics, inStem & NCBS, Bellary Road, Bangalore 560065, India.
  • 4 PhoreMost Ltd., Babraham Research Campus, Cambridge CB22 3AT, UK.
  • 5 Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK; PhoreMost Ltd., Babraham Research Campus, Cambridge CB22 3AT, UK.
  • 6 Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK; Center for Chemical Biology & Therapeutics, inStem & NCBS, Bellary Road, Bangalore 560065, India; PhoreMost Ltd., Babraham Research Campus, Cambridge CB22 3AT, UK. Electronic address: [email protected].
PMID: 34111400 DOI: 10.1016/j.chembiol.2021.05.009
Abstract

Genetic screening technologies to identify and validate macromolecular interactions (MMIs) essential for complex pathways remain an important unmet need for systems biology and therapeutics development. Here, we use a library of peptides from diverse prokaryal genomes to screen MMIs promoting the nuclear relocalization of Forkhead Box O3 (FOXO3a), a tumor suppressor more frequently inactivated by post-translational modification than mutation. A hit peptide engages the 14-3-3 family of signal regulators through a phosphorylation-dependent interaction, modulates FOXO3a-mediated transcription, and suppresses Cancer cell growth. In a crystal structure, the hit peptide occupies the phosphopeptide-binding groove of 14-3-3ε in a conformation distinct from its natural peptide substrates. A biophysical screen identifies drug-like small molecules that displace the hit peptide from 14-3-3ε, providing starting points for structure-guided development. Our findings exemplify "protein interference," an approach using evolutionarily diverse, natural peptides to rapidly identify, validate, and develop chemical probes against MMIs essential for complex cellular phenotypes.

Keywords

14-3-3; FOXO3a; bioactive peptide; lead discovery; phenotypic screening; prokaryal genomes; protein interference; protein-protein interaction; target identification; target validation.

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